This standard specifies the test method for determining the fineness of cement with Blaine air permeability tester. This standard is applicable to the determination of the specific surface area of cement and other various powdery materials with a specific surface area in the range of 2000cm2/g to 6000cm2/g, which are suitable for the method of this standard. It is not applicable to the determination Porous materials and ultrafine powder materials.